Portable ladders typically are made in the form of a pair or parallel side rails, interconnected by a plurality of uniformly spaced steps or rungs Such ladders may include fixed length structures, adapted to be leaned against the side of a vertical surface, or may be constructed in the form of two or more sections, slidably interconnected to form an extension ladder. Another variation is in the form of a foldable step ladder, in which the step section is interconnected or hinged near the top, with a fold-out extension to form a substantially triangular support; so that the ladder can be used as a free-standing ladder.
In the use of a conventional ladder, whether it is a step ladder or is adapted to be placed at an angle against a surface, the user typically ascends and descends the ladder by grasping upper rungs or sides of the ladder with the hands while moving the feet from step-to-step on lower rungs or steps of the ladder. If such a ladder is placed against a surface at too steep an angle, it is not uncommon for the center of gravity to be such that the ladder is quite unstable, and capable of tipping over backwards under the weight of the person using the ladder. In addition, the rungs or steps of the ladder do not provide a convenient handrail or handgrip; and, at least for some persons, the lack of any surrounding side supports leads to a sense of insecurity.
Efforts to provide some type of safety handle for ladders have been devised. One such device is disclosed in the patent to Hooser U.S. Pat. No. 4,293,055. This patent discloses a conventional step ladder to which a retractable safety handle has been added. The handle is made to extend substantially vertically alongside the weight-bearing step portion of the ladder to a position located above the top of the ladder. The safety handle is made so that it can be folded into a compact position when the ladder is folded up for storage. The handle is not intended to carry any weight, and it doss not extend parallel to the rails to which the steps of the ladder are attached.
Other patents which are directed to ladders or portable stairways having handrails are Begin U.S. Pat. No. 2,576,277; Hedglon U.S. Pat. No. 2,614,744; Tepper U.S. Pat. No. 2,640,641; and Guerette U.S. Pat. No. 4,044,857. All of these patents disclose ladders or portable steps where a handrail is attached to the main weight-bearing portion of the ladder to facilitate use of the device. The steps or rungs of the ladders, however, are attached to the weight-bearing portion, and the handrails simply extend outwardly above the main weight-bearing step portion of the ladder. The steps or treads of the ladder are not suspended from the handrails.
It is desirable to provide a safety ladder which provides an improved center of gravity over the ladder constructions of the prior art, and which utilizes handrails as the weight-bearing portion of the ladder.